Kenneth Folk, gives a short, but very clear definition of meditation in 3 minutes. Here is his website bio:
Kenneth is an instructor of meditation who has received worldwide acknowledgement for his innovative approach to secular Buddhist meditation. After twenty years of training in the Burmese Theravada Buddhist tradition of Mahasi Sayadaw, including three years of intensive silent retreat in monasteries in Asia and the U.S., he began to spread his own findings, successfully stripping away religious dogma to render meditation accessible to modern practitioners.
He has been recognized by Wired Magazine as an influential voice in Silicon Valley’s tech culture,